Design and laser damage properties of a dichroic beam combiner coating for 22.5-deg incidence and S polarization with high transmission at 527 nm and high reflection at 1054 nm

Journal Article · Wed Oct 12 00:00:00 EDT 2016 · Optical Engineering

DOI:https://doi.org/10.1117/1.oe.56.1.011020· OSTI ID:1340515

Bellum, John C. ^[1]; Field, Ella S. ^[1]; Kletecka, Damon E. ^[1]; Rambo, Patrick K. ^[1]; Smith, Ian C. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

We designed a dichroic beam combiner coating with 11 HfO₂/SiO₂ layer pairs and deposited it on a large substrate. It provides high transmission (HT) at 527 nm and high reflection (HR) at 1054 nm for a 22.5-deg angle of incidence (AOI), S polarization (Spol), and uses near half-wave layer thicknesses for HT at 527 nm, modified for HR at 1054 nm. The two options for the beam combiner each require that a high intensity beam be incident on the coating from within the substrate (from glass). We analyze the laser-induced damage threshold (LIDT) differences between the two options in terms of the 527- and 1054-nm E-field behaviors for air → coating and glass → coating incidences. This indicates that LIDTs should be higher for air → coating than for glass → coating incidence. LIDT tests at the use AOI, Spol with ns pulses at 532 and 1064 nm confirm this, with glass → coating LIDTs about half that of air → coating LIDTs. Lastly, these results clearly indicate that the best beam combiner option is for the high intensity 527 and 1054 nm beams to be incident on the coating from air and glass, respectively.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1340515
• Alternate ID(s): OSTI ID: 1331944
• Report Number(s): SAND--2016-9287J; 647550
• Journal Information: Optical Engineering, Journal Name: Optical Engineering Journal Issue: 1 Vol. 56; ISSN 0091-3286
• Publisher: SPIE
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
coatings on large optics
dichroic optical coatings
laser beam combining coatings
laser damage